An organic electro-luminescence (EL) panel is a self-emitting panel provided with an organic EL element (organic EL layer), and can be used as a lighting device, a light source, or a display device, for example. The emission color of the organic EL panel is determined by the material of the organic EL layer (light emission layer). Thus, when the organic EL panel is in practical use, the emission color is fixed already. On this account, it is generally impossible for a user to adjust the emission color (to perform color tuning) of the organic EL panel.
Under these circumstances, there has been proposed an organic EL panel configured so that organic EL layers for red, green, and blue (RGB) are formed separately, and color adjustment is achieved by adjusting the balance among the emission intensities of RGB (Patent Literature 1).